1997 Jeep Grand Cherokee annoying rubbing/ wooping sound

How you doin. I have a problem with my grand Cherokee. Now as a mechanic my self ive done a large number of repairs to this car for my mom and recently we did a bit of an overhaul on it. New springs, shocks, dampers, tires, joints and bushings, and brakes all the way around rotorsand pads. Then we got this rrubbing wooping sound in the rear so I checked it out and noticed brake rotor to pad rubbing so I checked wheel bearings and they were not the greatest (alot of play) so we replaced them thinking with the new ones the sound would stop. Well now it still happens but only after a bit of driving (when things have warmed up) I know its brake related but I cant think of what it would b ive switched the rotors to see if that would have an effect on the side the sound occurs but it hasnt. And actually the sound is more prominent after the bearings have been changed. Im leaning towards getting new rotors again thinking these ones are faulty/warped but id like an opinion. Another thought is the pads or the caliper bracket. Would shims help the pads I bought didnt have any with them so im unsure if its a possibility. Thank you and hope tto hear back soon.